Method of attaching conductors to brushes



. Dec. 1926.

- 1,612,336 G. c. WILSON ET AL METHOD OF ATTACHING GONDUCTORS TO BRUSHES Origirfal Filed Feb. 16. 1921 [/50], auoewtozs Patented Dec. 28, 1926.

UNITED STATES PATENT OFFICE.

GARDINER C. WILSON AND WILLIAM J. MILLS, OF ST. MEARYS, PENNSYLVANIA, .AS-

SIGNORS T0 STACKPOLE CARBON COMPANY, OF ST. MARYS, PENNSYLVANIA, A

CORPORATION OF PENNSYLVANIA.

METHOD OF ATTACHING CONDUCTORS TO BRUSHES.

Application filed February 16, 1921, Serial No. 445,317. Renewed May 28, 1926.

Our invention relates to a method of attaching conductors to brushes made of metal or of metal combined with other materials such as graphite, to be used in electrical generators and similar apparatus. Heretofore it has been customary to finish or substantially finish such brushes and then attach the conductors by solder or the like. Ve have discovered a method whereby the conductor can be very firmly attached and an excellent electrical connection obtained between the brush and the conductor at greatly reduced cost. This method consists essentially in forming the brush to its approximate shape with a hole or other aperture in the brush, inserting the conductor and then by pressure simultaneously giving the brush its desired form and clinching the conductor in place. By our I116tl10lwe are able to produce abrush to which the conductor is firmly attached both mechanically and electrically so that the resistance between the brush and the conductor will be low and there will be little likelihood of the conductor coming loose.

The manner in which our invention is to be carried out will be readily understood by reference to the accompanying drawings in which Fig. I shows a View of a, blank for a brush, partly in section with the conductor inserted; Fig. II shows another View also partly in section of the elements shown in Fig. I; Fig. III shows an elevation of the finished brush with the conductor fastened in placefFig. IV is a side elevation. of the brush shown in Fig. III, and Fig. V shows a form of spike that may be used if desired.

In the case of the illustrative example given here. the brush A in the form of a blank as shown in Figs. I and II was cut By virtue of the stamping operation the sides of the brush were smoothed off so that it would readily slide in the brush holder and there were formed the spring seat 2 and the concave contact surface 3. At the same time the metal surrounding the hole through which the conductor 13 was passed was compressed about the conductor B for a considerable distance, and the roughened spike C was forced into the sides of this hole and into the conductor '13 so that the conductor was firmly held in place.

13y exerting the pressure on the brush so as to form the spring seat 2, the metal of the brush is closely compressed about the conductor B near the central portion of the brush but the conductor is not materially distorted at the points where it emerges from the brush. This is an advantageous method of applying the pressure as it insures a good union between the brush and the conductor, and tends to prevent the strands of the conductor from being sheared ofi? at the points where the conductor emerges from the brush.

As is readily apparent, the principle herein described and the details of operation may be modified in many particulars and may be applied to brushes made of other materials than copper without departing from the spirit of our invention, for example, the conductor may be attached to the brush during an intermediate forming step and the brush may thereafter be given its final form as by grinding.

What we claim is:

1. The method of attaching conductors to brushes made of metal or metal compounds which comprises the steps of shaping the brush to its approximate form with a hole in itto receivea conductor, inserting a conductor and a piece of roughened metal into the hole and compressing the brush so that at the same time the brush is shaped and the piece of roughenedmetal is forced into the side of the hole and into the conductor so that the conductor is held firmly in place.

2. A method of attaching a. conductor to a brush of moldable material which comprises forming a hole in the brush, inserting a conductor and a metallic rod into the said hole, and compressing the material of the brush around the said coductor and rod.

3. A method of securing a conductor in a brush of moldable material which com- 5 prises passing the conductor into an opening in the brush,- inserting a spike into the said opening to force the said conductor said conductor so as to form arestriction therein lntermechate its ends.

GARDINER C. WILSON. WILLIAM J. MILLS. 

